DE102004021037A1 - Process for producing a high temperature resistant structure - Google Patents

Abstract

Method for producing a high-temperature-resistant structure (1), comprising at least one at least partially structured layer (2), comprising at least the following steps: DOLLAR A (a) applying an adhesive (3) to at least one connecting section (4) of the at least one layer (3) 2), wherein the adhesive (3) is applied dropwise to form an adhesive layer (5), so that a layer thickness (6) of the adhesive layer (5) of less than 0.05 mm is provided; DOLLAR A (b) at least partially shaping the structure (1); DOLLAR A (c) applying a solder material (7) so that it is at least partially fixed to an adhesive layer (5); DOLLAR A (d) Perform a thermal treatment. DOLLAR A The method allows in particular a precise gluing and Belotten metallic honeycomb structures, as they are preferably used for exhaust treatment in the automotive industry.

Description

The The present invention relates to methods for producing high temperature resistant Structures such as honeycomb bodies of metallic layers, which in particular as a catalyst carrier body, adsorber and / or filter body in Automotive engineering can be used.

From metallic layers wound, layered and / or twisted honeycomb body are known in many forms. An early design for which the DE 2902779 A1 typical examples shows is the spiral design, in which a smooth and a corrugated sheet metal layer is superimposed and spirally wound. According to another design of the honeycomb body is composed of a plurality of alternately arranged smooth and corrugated or differently corrugated sheet metal layers, the sheet layers initially form one or more stacks, which are entwined with each other. The ends of all sheet metal layers come to lie outside and can be connected to a housing, creating numerous connections that increase the durability of the honeycomb body. Typical examples of these designs are in EP 0245737 B1 or WO 90/03220.

Around a honeycomb body need to produce these layers are at least partially interconnected. For this Various connection techniques are known. Great importance in the market have brazing methods obtained in which the layers are brazed together at least in some areas. For this it is necessary, a solder material, which is a lower Melting point than the layers, to introduce into the honeycomb body. By heating the honeycomb body above the melting point of the solder material melts the solder and connects when cooled the Lay together.

The Solder material can be introduced into the honeycomb body in different forms be, for example, as a solder foil or solder powder. Lotfolie is in the areas where layers are to be interconnected, inserted or -glued while Solder powder (partly using a previously applied adhesive) is applied in certain areas of the honeycomb body.

Becomes the solder powder introduced without adhesive in the honeycomb body, is a targeted Fix the solder bodies in sections of the honeycomb body practically not possible. That means that for a locally inhomogeneous connection of the layers with each other (ie a Connection, in the flow direction and / or essentially transversely to the flow direction not consistent is) or the layers with a honeycomb surrounding the casing tube makes the application of an adhesive necessary.

Various techniques are known for applying the adhesive. For example, the EP 0422000 B2 the application of an adhesive by means of rollers. The order of the adhesive takes place here before winding or stacking the layers. Furthermore, for example, from the DE 10151487 C1 known, the adhesive in liquid form using capillary forces known. In this case, after the winding or stacking and twisting of the layers, the honeycomb body is brought into contact with a liquid adhesive which rises through the capillary forces into the capillaries formed by the contact regions of smooth and corrugated layers.

Both Methods described here are for a variety of different applications Well suited, however, is a particularly precise and precisely defined solder connection desired can However, technical difficulties occur. That's the job the adhesive by means of rollers relatively expensive, also is in particular the relative positioning of the rollers with respect to those with adhesive to be provided layers error prone. Furthermore, the introduction of the adhesive by means of capillary forces allows no selective connection of adjacent layers only in subareas in a sufficiently flexible way Dimensions.

Of these, It is an object of the present invention, a method specify the technical problems of known methods for Production of high temperature resistant structures at least reduces. In particular, a method is to be specified, which is a precise Beloten the structure allows. Here are the criteria of an at least semi-automatic Serial production taken into account become. Ultimately, it should also be a high temperature resistant structure can be provided the considerable thermal and dynamic stresses, for example in the exhaust system permanently with mobile internal combustion engines. Also From the point of view of cost, an effective use of soldering material is intended favored become. In addition, it is also desired that in comparison with similar ones known methods require less energy to carry out the process is.

These objects are achieved by the method having the features of the independent claim. Further advantageous embodiments of the method are the subject of dependent formulated claims. It should be noted that the features mentioned there or process steps in any techno logically meaningful way can be combined with each other, wherein further embodiments of the method according to the invention are shown.

• (a) Auftragen eines Haftmittels auf wenigstens einen Verbindungsabschnitt der mindestens einen Lage, wobei das Haftmittel zur Ausbildung einer Haftschicht tropfenförmig appliziert wird, so dass eine Schichtdicke der Haftschicht kleiner 0,05 mm (Millimeter) bereitgestellt wird;
• (b) zumindest teilweises Formen der Struktur;
• (c) Applizieren eines Lotmaterials, so dass dieses zumindest teilweise an einer Haftschicht fixiert wird;
• (d) Durchführen einer thermischen Behandlung.

The method proposed here for producing a high-temperature-resistant structure which comprises at least one at least partially structured metallic layer has at least the following steps

• (A) applying an adhesive to at least one connecting portion of the at least one layer, wherein the adhesive for applying an adhesive layer is applied drop-shaped, so that a layer thickness of the adhesive layer less than 0.05 mm (millimeters) is provided;
• (b) at least partially shaping the structure;
• (c) applying a solder material so that it is at least partially fixed to an adhesive layer;
• (d) performing a thermal treatment.

Under An adhesive is understood in particular to mean a substance which is suitable to fix solder material (at least temporarily) until this finally conducted thermal treatment is melted. These adhesives usually have the ability on, other bodies (here the layer and the solder material) by strong surface adhesion (Adhesion) and strong internal cohesion.

According to step (a), this adhesive is now applied to at least one connecting section. The connecting portion is the area provided for the provision of adhesive on the sheet. The connecting portion may, for example, extend in the form of a strip or similarly over a larger portion of the layer, but it is also possible that the connecting portion only locally narrowly limited portions (eg with an area smaller than 20 mm ² or even smaller than 10 mm ² or less than 5 mm ² ) means the situation. The connecting section is thus not necessarily equated with the area in which ultimately the technical joining of the layers is generated.

The formed adhesive layer is accordingly by a teardrop-shaped order of the adhesive provided. This has the advantage that the application without mechanical contact between the means for application of the adhesive and the situation itself can be performed. With that on the one hand mechanical damage avoided the situation, at the same time it is possible in this way, one exactly dosed, predetermined small amount of the adhesive on the Able to arrange. So here is the opportunity created at the same time, especially thin layer thicknesses to provide the adhesive layer, in particular less than 0.05 mm. The very small layer thickness opened now the possibility of the Adhere adhesive effect of the adhesive itself, since the contact surface or the penetration depth of the solder material used can be influenced. The teardrop-shaped Providing the adhesive allows even thinner layer thicknesses. So it is also suggested that the layer thickness is still significant made smaller is, e.g. less than 0.01 mm, 0.001 mm (1 μm), especially less than 0.0005 mm (0.5 μm), or even less than 0.0001 mm (0.1 μm). The achievable layer thicknesses hang in a certain way also with the adhesive used together; so can be extremely thin For example, make adhesive layers with those that have a high Solvent content (e.g., greater than 50%). Such extremely thin Layer thicknesses were previously not in the context of a series production to realize. The application by mechanical means would often destroy the Adhere adhesive layer or at least would require considerable time and expense.

According to step (b) becomes at least partially after the application of the adhesive shaped the structure. This means in particular that a plurality be stacked by layers so that they form flow channels, by convention be bounded at least two adjacent layers. These can be the Layers are also connected or wound together, so that ultimately creates a kind of honeycomb structure. It is not necessarily necessary, the final desired Form the structure already at this procedural stage, rather, it is also possible that the shaping of the structure is interrupted, and further process steps carried out for example, again step (a) and / or step (c).

Solder material is then applied by method step (c) so that it is at least partially fixed to the adhesive layer. It should be noted that step (c) can also be carried out at least partially directly after step (a), ie, the application of the solder material takes place even before the at least partial shaping of the structure. The provision of the brazing material may take place in any known manner, but preferably the brazing material is conveyed through the structure with a carrier stream (for example air), whereby it comes into contact with the layers and thus also with the adhesive layer. If the soldering material encounters such an adhesive layer, it usually adheres there. The solder material, which does not come into contact with adhesives as it flows through the structure, is collected again, optionally cleaned, and recycled to the process to provide an environmentally friendly and cost effective process. Now, the desired amount of the solder material is in the intended connection sections between adjacently arranged subsections of the layer or the layers. This amount of solder material has been determined taking into account the required fatigue strength under thermal and / or dynamic cycling, as it takes place for example in exhaust systems of mobile internal combustion engines. In addition, it is considered that this Lotmenge in the thermal treatment has no (eg chemical) material change of the metallic layer result, so this example remains permanently resistant to corrosion.

in the Process step (d), the solder material is then melted and finally generates on cooling joining technology Compounds such that e.g. the majority of layers are captive with each other are connected. The thermal treatment is preferred a high-temperature vacuum process. Becomes the structure of an elevated temperature suspended, so start first certain proportions of the adhesive to change their state of aggregation, in particular to evaporate. After all evaporates almost all of the adhesive, so that the compound essentially exclusively by the solder material provided there is generated. It is preferred performed this thermal treatment in a soldering oven, it but it is also possible a heating by inductive soldering and / or radiation brazing and / or by the waste heat a welding process to reach.

• – Drop-on-Demand-Verfahren;
• – Bubble-Jet-Verfahren;
• – Continuous-Jet-Verfahren.

According to a preferred embodiment of the method, the adhesive is printed by means of one of the following methods:

• - drop-on-demand procedure;
• - bubble-jet method;
• - Continuous jet process.

The The aforementioned methods are used in particular for the separation or formation of drops from a liquid reservoir and to targeted positioning of the drop or for directional transport drop to a target site.

"Drop-on-demand" procedures are printing processes, which are characterized in that a drop of the adhesive only then generated when it is actually needed. With that it creates a kind of discontinuous delivery method for adhesive drops That is in other words, the application of the adhesive is so takes place, that a relative movement between position and the device to carry out the drop-on-demand procedure is realized, this device only then drops generated and emitted when these are in the range of a desired Connecting portion is located. In the event that this device outside the connecting portion is positioned, no drops generated and emitted.

at For example, drop-on-demand systems allow for single drops of To produce adhesive by means of piezoelectric actuators. For piezoelectric Actuators are electromechanical converters that are located on the based piezoelectric effect. This results in the application of an AC voltage to the piezoelectric element to mechanical vibrations. This vibration is transferred to a given adhesive volume, which is on a Each outlet forms a drop, which then with a relatively high Speed of a nozzle is supplied. There are several known drop-on-demand methods, the piezoelectric ones Transducers are based, for example Piezoröhrchen, piezo discs, piezo lamellae.

One preferred drop-on-demand method is the "bubble jet" method the adhesive drops not by means of a piezoelectric transducer but by using thermal actuators. These are usually heating elements, which are formed in a nozzle and with the Adhesives are connected. These heating elements will temporarily in the nozzle a localized area brought to a very high temperature, the significantly over the boiling point of the adhesive is. The adhesive begins then to boil locally, resulting in a closed after a very short time Steam bubble forms. This vapor bubble drives a drop of the adhesive out of the nozzle, taking pressures of 10 bar or more and exit speeds of 10 m / s (meters per second) and more can be achieved. This vapor bubble then collapses, causing it it due to the capillary forces for sucking in adhesive in the nozzle comes. In such bubble jet method There are various printing techniques that are commonly used are known as "Edge-" and "Sides-Hooter".

In addition to these drop-on-demand processes, there are also continuous printing processes in which a continuous stream of adhesive drops is produced which, when drops are needed, leaves the device and is otherwise deflected so that the generated drops are guided into a catch tank and thus not reach the surface to be printed. Such a method is also the "continuous inkjet" method or "continuous jet" method herein, wherein the continuous stream of drops is generated by positioning the printhead and / or electrostatic deflection with a desired beam direction. When such a continuous jet method is used to apply adhesive, a continuous steel of adhesive drops is produced which is in a catch tube is directed, which finally supplies the adhesive back to the reservoir. If now the beam to be directed to the predetermined connecting portions, there is a deflection of the droplet jet in the interior of the system, so that the beam leaves the device and impinges on the desired connecting portion.

The Application of the adhesive by means of the abovementioned methods leads to that very small drops with very high speed and very precise can be applied to the situation. For example, generating a drop with a Frequency of about 50 kHz (50,000 drops per second), if necessary even with even higher ones Frequency. Such high-frequency processes have high production speeds As a result, especially with regard to a series production advantageous to make such structures noticeable.

Corresponding In a further development of the method, the adhesive is statically chargeable and preferably has an electrical conductivity greater than 1.0 mS (milli Siemens). Preferably, the electric conductivity at most 5.0 mS and in particular at most 2.0 mS. Static charging of the adhesive makes it possible to that a deflection of the generated adhesive droplet jet through an electric field can take place. This has the consequence that it is not mandatory to use the device for carrying out the teardrop Order itself must be moved relative to the situation, but can the beam formed itself pivoted or deflected become. additionally open the opportunity in a continuous provision of a droplet jet one Distraction to cause precisely when the drops are directed into a collection container should be because outside There is no need for adhesive drops in the device.

According to one Another embodiment of the method adhesive is used, which is a dynamic viscosity in the range of 3.0 to 5.0 mPa (milli Pascal). Prefers is the dynamic viscosity in a range of 3.5 to 4.5 mPa. Under a viscosity is in particular the tenacity of the adhesive understood. Certainly she can do it, for example be that solid body at a speed through the quiescent adhesive liquid is moved through, in which case in general to maintain The movement requires a force that varies in size and shape of the body and a property of the liquid, the dynamic viscosity, depends. The determination of the dynamic viscosity presents no problems for the person skilled in the art in which the values given here for the room temperature and the atmospheric pressure be valid. The dynamic viscosity is especially for the formation of drops inside the device for applying the Adhesive of importance. Is the dynamic viscosity in the specified area ensures that sufficient flow is present, the drops separate after charging and thus keep their cargo. This ensures the later following Distraction of the drops.

Further It is also suggested that the adhesive should have a solvent content which is at least 50%. Preferred is this solvent content at least 70%, especially 90%, and most preferably at least 98%. As a solvent preferably come low-viscosity, polarizable solvent used, in particular acetone and / or ethanol.

moreover it is proposed that the adhesive has an adhesive content, up to at least 300 ° C (Degrees Celsius) resistant is. This is to ensure be that the adhesive property of the adhesive up to at least this temperature is present. So can For example, thermal pre-treatment measures are taken, and the solder material remains until the final thermal treatment at the desired Adhere connecting section. It is particularly preferred that a constant adhesive property is present up to approx. 150 ° C, about that however, this can change. Decisive is that at 300 ° C still one such adhesive property is that the solder material adhere to it remains. The adhesive may be in addition to the polarizing solvent, especially water or organic solvents, including other ingredients have, e.g. Resins, hardeners, fillers, additions such as plasticizers, thickeners, preservatives, etc ..

Furthermore, it is also proposed that the structure is subjected to a thermal pretreatment before the application of the solder material. This means in particular that this thermal pretreatment is carried out before at least one of the steps (c), (b), (a). The thermal pretreatment comprises in particular a cleaning of the layer, for example of volatiles, which have formed on the sides or the surface of the layer. These impurities, equipment, etc. could adversely affect the application of the adhesive or the application of the solder material. With regard to the adhesive, the adhesion effect to the layer could be disturbed. In addition, it is also possible that these impurities also have an adhesion to the solder material used, so that unwanted solder joints would arise. In addition, it should be noted that especially in the configuration of the final thermal treatment as a vacuum process, the volatile constituents a disorder of the vacuum can result. Therefore, it is proposed here to remove at least the volatile constituents from the layer as part of a thermal pretreatment. This thermal cleaning takes place, for example, at temperatures in the range above 200 ° C, in particular in the range of 250 ° C to 350 ° C. If this thermal pretreatment is carried out after step (a), the solvent constituents of the adhesive can be removed at the same time so that these volatile constituents likewise do not hinder the downstream thermal joining process. In view of the fact that some of the resources are used to ensure reliable molding of the structure, the thermal pretreatment is preferably carried out between steps (b) and (c).

According to one advantageous development of the method, the adhesive with at least one nozzle applied, wherein the at least one nozzle defines a beam angle and a distance from the connecting portion, wherein for training an adhesive layer at least one of the parameters beam angle and Distance is varied so that the adhesive layer with a given Layer thickness and / or layer expansion is generated.

at The aim of the above-mentioned method is to achieve, when provided the same drop size respectively of the same adhesive volume per drop by variation alone the distance and / or the beam angle different area of Able to wet. The "distance" describes it essentially the length the free trajectory of the adhesive drop from the exit from the Nozzle until the Impact on the situation. By "beam angle" is meant the angle between a vertical through the connecting portion and the impact direction of the drop is formed. The variation This beam angle has a different configuration of the Drop in contact with the situation result. Is the application carried out of the adhesive parallel to the vertical, so with a beam angle from 0 ° (degrees), so is in a planar design of the connecting portion form a substantially round spot of impact. In the case, that, for example, an oblique Impact direction or a beam angle, in particular greater than 45 ° to the vertical chosen becomes, forms a substantially oval or asymmetrical Impact spot off. This makes it possible, by an oblique spraying the Location a larger area of Wipe the connecting portion with adhesive. This leads at the same time to a reduced layer thickness, since per drop the same volume or the same mass is provided. The nozzles have preferably a diameter of 0.5 to 0.6 mm. On the Location or in the connecting section are so Auftreffflecke the Size about 0.05 to 0.7 mm, in particular in the range of 0.1 to 0.5 mm and preferably in the range of 0.2 to 0.3 mm.

one Another embodiment of the method results in solder material as a powder with a particle fraction smaller 120 microns (microns) applied. It is preferred doing a grain fraction used, the average size smaller Has 106 μm, in particular in a range of 63 to 106 microns, a range of 36 to 75 μm, one Range from 40 to 60 μm or a range of 60 to 80 μm. The solder used is preferably a nickel-based solder. The vote the suitable grain fraction is in particular with the trained Matching adhesive layer. Make the different lot grain fractions each different peripheral surfaces ready, which finally the Affect adhesion in the connecting section. The peripheral surfaces and The masses of the solder grain powders are therefore taking into account the given or desired Select compound and the formed adhesive layer.

mit

m

_Lot: erforderliche Lotmasse,

δ_Lot:

Lotmaterialdichte,

d

_Lot: gemittelter Durchmesser des pulverförmigen Lotmaterials,

s:

Foliendicke,

1:

Länge des Haftmittelstreifens.

If the structure is formed with at least one smooth film and one corrugated film of a predetermined film thickness, which form contact points with gussets, it is proposed that a quantity of solder material be applied which corresponds at least to the following relationship, depending on the film thickness in a gusset:

With

m

_Lot : required solder mass,

δ _lot :

Lotmaterialdichte,

d

_Lot : average diameter of the powdery solder material,

s:

Film thickness;

1:

Length of the adhesive strip.

The Quantity specified here describes the minimum required quantity of the soldering material for warranty a permanent connection. Usually This minimum value should not be more than 5 times, in particular not more than 3 times or even 2 times.

The structure described here has at least one smooth film and one corrugated film. Both are preferably made of a high temperature resistant metallic material, which contains in particular aluminum and / or chromium. The film thickness of at least one of the films is preferably in a range of less than 130 μm, in particular less than 60 μm. If such a corrugated foil is placed on a smooth foil, contact points develop along the extremes of the corrugated foil. Directly adjacent to this contact point are gussets (here as generic term for Ein bays, gaps, etc.). Depending on the configuration of the extremes, these gussets open very quickly or are relatively flat. These gussets provide the space for the finally formed solder joints. Now it is proposed that only a very specific amount of soldering material is provided in these gussets.

at an embodiment of the structure with at least one smooth film and a corrugated foil is also suggested that the at least a corrugated foil by means of a shaping rolling process under Use of an oil is produced, in which the produced corrugated foil is de-oiled, before the adhesive is applied. The production of a corrugated Film from a smooth film by means of a shaping rolling process belongs to the usual Sheet metal working in this technical field. The use of the oil ensures that roll the rollers well on the surface during the shaping and thus the Do not damage the foil. Because this oil in certain circumstances impairs the further procedure of the method described here, should the oil be removed before the adhesive is applied. The removal can be done thermally, mechanically and / or chemically. When used it is easily volatile oils in certain circumstances sufficiently, a correspondingly large volatilization transport route so that at the time when the film wets with the adhesive should be, at least a large part of the oil already evaporates is.

In addition, will also suggested that in a structure that with at least a smooth film and a corrugated film is formed, the corrugated foil has extrema, wherein in addition to at least one extremum extending, at least one adhesive layer with a distance of at least 0.05 mm (millimeters) is generated. In particular with Extrema meant the highs or lows of the structure, for example, the mountains and valleys a wavy one Structure. These extremes usually run in a straight line So a kind of crest line. With the method proposed here is it possible now especially close to this extremum approach to form such adhesive layers, wherein at the same time it prevents the extremum itself, which eventually the Forms contact with adjacent films, free of adhesives is. The proposed distance also has the consequence that in direct Neighborhood of Extrema no adhesive is placed, which can not be reached by the solder due to the grain fraction can. This also allows, for example, when shaping the structure Slide the film together because in the area of the contact points no adhesive is present. Preferably, the distance is in an area from 0.05 to 0.1 mm. In particular, the limitation of Adhesive layer used, which is closest to the extremum.

In In this context, it is particularly advantageous if the adhesive layer has a layer width smaller than 0.9 mm (millimeters). Especially the layer width is in a range of 0.15 mm to 0.3 mm. With such precision positioned and narrow trained adhesive layers can be the solder material even in part, except for the grain exactly in one Apply gusset. this makes possible a previously unavailable precision the connection technology in the field of production of honeycomb body for exhaust gas treatment plants.

According to one Development of the method for producing a structure with at least one smooth film and a corrugated film, wherein has the corrugated foil Extrema, it is proposed that at least the number or locations of extrema are recorded. To be favoured both the number and the location of the extremes recorded. That means first once, that counting or monitoring devices are provided, which recognize the location of the extremes or to register. This is preferred over the entire manufacturing process tracked. This will be the opportunity created to assign the adhesive layers to specific extremes, so that a variety of different patterns are applied to the slides can be. It is also possible, thus generating three-dimensional patterns in the fabricated structure, the structure being different in very specific areas Lotverbindungen trains, or partial volumes without solder joints are provided. The detection of the extrema can, for example, by the shaping rollers, additional Sensors or others for this appropriate funds are made.

In monitoring or regulating the production process of a film, in particular the production of an adhesive layer and / or the Belotens, it may be advantageous to use an adhesive whose position, position and / or shape can be detected by measurement. By this is meant in particular that the adhesive comprises means which allow optical detection. Thus, for example, a special color or coloring may be present, which ensure the automatic recognition of the adhesive layer by means of measured value acquisition units, in particular sensors. If the adhesive has such a color, the adhesive can be identified, for example, by means of a stroboscopic radiation and a detected, modified reflection on the surface of the film. Furthermore, it is also possible that the different refraction of a light beam directed onto the film is used to detect the adhesive layer. This differs, for example recognizable, when a dry or an adhesive wetted surface (eg with a laser) is scanned. The obtained measured values can be one Superordinate control unit are supplied so that they allow statements about the nature or quality of the films produced or make a variation or adjustment of the process parameters. Of course, this method can also be carried out after the Beloten, which under certain circumstances can even draw conclusions about the Belotungsmenge.

• – Kontinuierliches Erzeugen einer Wellung in einer glatten Folie infolge Hindurchführens durch ineinandergreifende Profilwalzen;
• – kontinuierliches Entfernen von an der gewellten Folie haftendem Öl;
• – Applizieren wenigstens einer Haftschicht auf einer ersten Seite der gewellten Folie gemäß Schritt (a);
• – Trennen der Folie mit eine vorgebbaren Erstreckung;
• – Stapeln mindestens einer glatten Folie und einer gewellten Folie zu einer Struktur;
• – zumindest teilweises Einbringen der Struktur in ein Gehäuse;
• – Applizieren eines pulverförmigen Lotmaterials zu der wenigstens einen Haftschicht;
• – Durchführen einer thermischen Behandlung zur Ausbildung von Lötverbindungen.

A preferred embodiment of the method results in a structure having at least one smooth foil and one corrugated foil, wherein the following steps are carried out:

• - Continuously generating a corrugation in a smooth film as a result of passing through intermeshing profile rollers;
• - Continuous removal of adhering to the corrugated foil oil;
• Applying at least one adhesive layer on a first side of the corrugated foil according to step (a);
• - Separating the film with a predetermined extent;
• Stacking at least one smooth film and one corrugated film into a structure;
• - at least partially introducing the structure into a housing;
• - Applying a powdered solder material to the at least one adhesive layer;
• - Perform a thermal treatment for the formation of solder joints.

The The aforementioned method is particularly suitable for the production of honeycomb bodies, as the carrier body in Exhaust systems of automobiles are used. The production takes place in series, with the proposed here continuous Procedures are easy to integrate into existing manufacturing processes leaves.

at Special applications can also be a two - sided wetting of the corrugated foil with adhesive, e.g. in front the following method step is carried out when separating the films: Apply at least one adhesive layer on a second side the corrugated foil according to step (A).

With the method described here can be the connecting sections make it free in a hitherto unknown way. The connecting sections can in a structure or in a honeycomb body now not only axially but also be arranged radially offset from each other. That means, that the connecting sections now according to the thermal and dynamic loads of the honeycomb body in use targeted can be. Especially for very large volume Honeycombs, For example, as a catalyst carrier body in exhaust systems of trucks are used, such offset solder joints to compensate for thermal differential expansions advantageous. This is especially true with honeycomb bodies with Diameters in a range of 150 mm to 450 mm.

The here representational A method for producing a high temperature resistant structure will be described below closer to the figures explained. It should be noted that the figures particularly preferred Embodiments of the method or the thus produced Structure or semi-finished products represent, to which the However, the invention is not limited. Show it:

1 An embodiment of a high temperature resistant structure;

2 a detail of the high temperature resistant structure in perspective view;

3 a schematic representation of the application of adhesives by means of nozzles;

4 schematically the flow of a preferred method for producing a honeycomb body.

The 1 shows schematically and in a perspective view of an embodiment of a high temperature resistant structure 1 , as for example as a carrier for different coatings 29 used for exhaust treatment in the automotive industry. The structure 1 here includes a housing 26 in which a partially structured location 2 is arranged from metal. The location 2 has smooth and structured subregions and is wound so that for the exhaust gas flow through channels 28 are formed. The smooth sections of the location 2 form contact points with the structure or corrugation 15 , near where finally the solder joints 27 are designed. Other solder joints 27 be between the location 2 and the housing 26 educated. Near the contact points 15 The adjacent or adjoining layer sections form so-called gussets 16 in which ultimately the solder joint 27 is trained. In the illustrated embodiment, the structure has 2 essentially a so-called "race-track" -form, but in principle also round, polygonal or other cross-sectional shapes are possible.Here is the structure 1 with layers of a stretch 37 formed, which is also an extension of the housing substantially 26 which does not necessarily have to be the case. In the illustrated embodiment, the solder joints 27 over the cross section of the structure 2 equally distributed. Grundsätz However, it is possible and is particularly easy to implement by the method proposed here, the structure 1 over the cross section or in the direction of expansion 37 with differently formed solder joints 27 perform. This creates a special thermal expansion behavior of the structure 1 generated at thermal cycling, which determines the durability of the structure 1 can favor.

2 now shows (also in a schematic perspective view) a detail of a structure 1 that with a smooth foil 12 and a corrugated foil 13 is formed. Here are the smooth films 12 and the corrugated foils 13 alternately arranged to each other so that in turn channels 28 are formed. The corrugated foil 13 has Extrema 19 on, which are finally the contact points 15 the smooth films 12 and the corrugated foils 13 represent. Close to these extremes 19 are gussets 16 formed, in which later the solder material 7 should be arranged so that it for the subsequent training of joining solder joints 27 present at the contact points.

For fixing the solder material 7 in the gussets 16 or at other desired locations or connection sections 4 are the films with an adhesive layer 5 Mistake. The adhesive layer 5 comes with adhesive 3 generated, which is applied drop-shaped. This allows the adhesive layers 5 according to the desired connection section 4 make it very precise. Here are mainly stripe-shaped adhesive layers 5 however, it may be any form of adhesive layer 5 with almost any layer expansions 11 to be generated. In the illustrated embodiment, the smooth film 12 with a substantially transverse or perpendicular to the extremum 19 extending adhesive layer 5 provided, this over several corrugations of the corrugated foil 13 is formed coherently. At the corrugated foil 13 are only very narrow stripes near the gussets 16 provided, this with a distance 20 and parallel to the extremes 19 are formed. The layer width 21 is advantageously in a range of less than 1 mm.

The representation is a detail of the structure 1 before it is subjected to thermal treatment to form joining compounds. The solder material 7 is provided here as a powder or in granular form of a given grain fraction, according to the prepared adhesive layers 5 a predetermined amount of solder material 7 sticking inside the structure. This can be over a length 17 the gusset 16 bring in a defined amount of solder. In a subsequent thermal treatment, a large part of the adhesive volatilizes 3 , wherein the solder material 7 , which is arranged near the gussets, the adjacently arranged foils together and thus ensures a permanent cohesion of the films.

3 shows schematically the application of the adhesive 3 with a nozzle 8th to form an adhesive layer 5 with a layer thickness 6 less than 0.01 mm. Applying the adhesive 3 This is the example of a corrugated foil 13 explained. Usually, this is the corrugated foil 13 relative to the illustrated nozzles 8th moved, in particular guided between them. This allows for an adhesive layer first 5 on a first page 23 the corrugated foil 13 is generated while subsequently also on the second page 24 by means of another nozzle 8th an adhesive layer 5 can be trained. The amount of adhesive 3 or the embodiment of the adhesive layer 5 takes into account the amount of solder finally required for the compound, which also with respect to the film thickness 14 the corrugated foil 13 was chosen. To make a simple adjustment here are the nozzles 8th pivotable and / or relatively movable to the corrugated foil 13 educated. The nozzles 8th are with respect to their beam angle 9 and their distance 10 changeable executed. With distance 10 is as shown, the distance of the nozzle opening to the point of impact of the drops 36 of the adhesive 3 meant. The beam angle 9 determined by the direction of flight of the drops 36 and the vertical 35 through the impact point on the corrugated foil 13 or in the desired connection section 4 , It should be noted that the distance 10 or the beam angle 9 the two nozzles 8th may each be chosen differently from each other.

4 schematically shows the sequence of a preferred embodiment of the method for producing a high temperature resistant structure 1 containing a plurality of smooth films 12 and corrugated foils 13 having. The progress of the process is indicated by white arrows, the figure is constructed line by line and is always read from left to right.

Starting with a smooth foil 12 for example, on a spool 30 is stored, first the desired curl in the film 12 brought in. This is the smooth film 12 first with oil 18 brought into contact just before the smooth slide 12 by intermeshing profile rollers 22 is passed through, in order to promote the process of transformation taking place. Following this forming process, the now corrugated foil 13 through an oven 31 passed, which is the wavy film 13 sticky oil 18 at least for the most part volatilized. The thus cleaned corrugated foil 13 is now a system for Forming the desired adhesive layers supplied, which here by two nozzles 8th symbolized on both sides 23 . 24 the corrugated foil 13 are arranged. To form extremely thin adhesive layers or particularly precisely positioned adhesive layers, the adhesive 3 printed by means of a drop-on-demand method, a bubble jet method or a continuous jet method, wherein it is basically also possible to use a separate method for each nozzle or to provide a plurality of such processing stations, each having different adhesive layers train and use a different procedure. This prepared corrugated foil 13 now becomes a cutting device 32 fed, which the corrugated foil 13 with a predeterminable extent 25 separates. The corrugated films thus produced 13 be with smooth slides 12 (for example from another coil 30 ) alternately to a structure 1 stacked. This stack preferably forms channels 28 , which are at least partially flowed through by an exhaust gas.

This stack is now wound in the embodiment of the method described here still S-shaped, with a substantially cylindrical shape is formed. Also such structures 1 For example, as a honeycomb body 33 designated. The honeycomb body thus formed 33 or the structure thus formed 1 will now be in a housing 26 integrated. The structure 1 will now over the front page, so for example through the channels 28 through, with solder 7 brought into contact. Here is this contacting the solder 7 in powder form by means of a so-called fluidized bed 34 in which a carrier medium (air), the solder material 7 through the structure 1 transported through. The desired amount of solder material remains 7 on the previously generated adhesive layers 5 glue. The honeycomb body equipped with solder material 33 or the structure thus produced 1 is now subjected to a thermal treatment, here again in an oven 31 is carried out. This is preferably the high-temperature vacuum brazing.

The The method described here is particularly suitable for the production of thermally and dynamically highly loaded metallic honeycomb bodies. The achievable accuracy with respect the formation of adhesive layers and the resulting targeted Introduction of a desired amount of solder to desired Positions allows a very precise tuning of the solder joints to the respective application encountered. In particular it is possible, very defined the thermal and dynamic behavior of the structure or the honeycomb body to determine pressure and temperature. This will in particular prolongs the life of such structures in exhaust systems of automobiles the production is made more cost-efficient, since in each case only as much solder material is introduced, as is actually the case for the connection is required.

1

structure

2

location

3

adhesives

4

connecting portion

5

adhesive layer

6

layer thickness

7

solder

8th

jet

9

beam angle

10

distance

11

layer expansion

12

smoothness foil

13

corrugated foil

14

film thickness

15

contact point

16

gore

17

length

18

oil

19

extremum

20

distance

21

layer width

22

corrugated roll

23

First page

24

Second page

25

extension

26

casing

27

solder

28

channel

29

coating

30

Kitchen sink

31

oven

32

cutter

33

honeycombs

34

fluidized bed

35

vertical

36

drops

37

expansion

Claims (15)

Method for producing a high-temperature-resistant structure ( 1 ) comprising at least one at least partially structured metallic layer ( 2 ) comprising at least the following steps: (a) applying an adhesive ( 3 ) on at least one connecting section ( 4 ) of the at least one layer ( 2 ), wherein the adhesive ( 3 ) for forming an adhesive layer ( 5 ) is applied drop-shaped, so that a layer thickness ( 6 ) of the adhesive layer ( 5 ) less than 0.05 mm; (b) at least partial shaping of the structure ( 1 ); (c) applying a solder material ( 7 ), so that this at least partially on the adhesive layer ( 5 ) is fixed; (d) performing a thermal treatment. Process according to claim 1, in which the adhesive ( 3 ) is printed by one of the following methods: - drop-on-demand method; - bubble-jet method; - Continuous jet process. Method according to claim 1 or 2, wherein the adhesive ( 3 ) is statically chargeable and preferably has an electrical conductivity which is greater than 1.0 mS. Method according to one of the preceding claims, in which the adhesive ( 3 ) has a dynamic viscosity in the range of 3.0 to 5.0 mPa. Method according to one of the preceding claims, in which the adhesive ( 3 ) has a solvent content that is at least 50%. Method according to one of the preceding claims, in which the adhesive ( 3 ) has an adhesive content that is resistant to at least 300 ° C. Method according to one of the preceding claims, in which the structure ( 1 ) before applying the soldering material ( 7 ) is subjected to a thermal pretreatment. Method according to one of the preceding claims, in which the adhesive ( 3 ) with at least one nozzle ( 8th ) is applied, wherein the at least one nozzle ( 8th ) a beam angle ( 9 ) and a distance ( 10 ) to the connection section ( 4 ), wherein to form an adhesive layer ( 5 ) at least one of the parameters beam angle ( 9 ) and distance ( 10 ) is varied so that the adhesive layer ( 5 ) with a predetermined layer thickness ( 6 ) and / or layer extent ( 11 ) is produced. Method according to one of the preceding claims, in which the solder material ( 7 ) is applied as a powder with a particle size less than 120 microns. Method according to one of the preceding claims, in which the structure ( 1 ) with at least one smooth film ( 12 ) and a corrugated foil ( 13 ) a predetermined film thickness ( 14 ), which contact points ( 15 ) with gussets ( 16 ), whereby a lot of solder material ( 7 ) is applied, which depends on the film thickness ( 14 ) in a gusset ( 16 ) corresponds to at least the following relationship:

with m _solder : required solder mass, δ _solder : _solder material density, d _solder : average diameter of the powdered solder material, s: film thickness, l: length of the adhesive strip. Method according to one of the preceding claims, wherein the structure ( 1 ) with at least one smooth film ( 12 ) and a corrugated foil ( 13 ), wherein the at least one corrugated foil ( 13 ) by means of a shaping rolling process using an oil ( 18 ), in which the produced corrugated foil ( 13 ) is de-oiled before the adhesive ( 3 ) is applied. Method according to one of the preceding claims, wherein the structure ( 1 ) with at least one smooth film ( 12 ) and a corrugated foil ( 13 ) and the corrugated foil ( 13 ) Extremes ( 19 ), in which besides at least one extremum ( 19 ), at least one adhesive layer ( 5 ) with a distance ( 20 ) of at least 0.05 mm. Process according to claim 12, in which the adhesive layer ( 5 ) a layer width ( 21 ) smaller than 0.9 mm. Method according to one of the preceding claims, wherein the structure ( 1 ) with at least one smooth film ( 12 ) and a corrugated foil ( 13 ) and the corrugated foil ( 13 ) Extremes ( 19 ), in which at least the number or position of the extrema ( 19 ). Method according to one of the preceding claims, wherein the structure ( 1 ) with at least one smooth film ( 12 ) and a corrugated foil ( 13 ), in which the following steps are carried out: - continuous production of a corrugation in a smooth film ( 12 ) as a result of passing through interlocking profile rollers ( 22 ); Continuous removal of corrugated foil ( 13 ) adhering oil ( 18 ); Applying at least one adhesive layer ( 5 ) on a first page ( 23 ) of the corrugated foil ( 13 ) according to step (a); - separating the film ( 12 . 13 ) with a predefinable extension ( 25 ); Stacking at least one smooth film ( 12 ) and a corrugated foil ( 13 ) to a structure ( 1 ); - at least partial introduction of the structure ( 1 ) in a housing ( 26 ); Application of a powdered soldering material ( 7 ) to the at least one adhesive layer ( 5 ); Performing a thermal treatment to form solder joints ( 27 ).